Make preview images larger

[stscijgbot-jwql]

Issue JWQL-214 was created on JIRA by Bryan Hilbert:

From the JWQL user survey (NIRISS team):

Make the preview jpegs bigger. It would be great if these were up to 2x bigger, I think it would be much easier to spot anomalies. While I'm on it, might help to scale the colorbar to the plot height, which could then let you increase the overall jpeg size

The submitted mentioned that this is one of their top 3 improvements, priority wise.

Preview image size probably can't get much larger in the case of exposure level pages for NIRCam and maybe NIRSpec. But at the detector level pages, they could be made larger. Scaling the size of the colorbars would be helpful as well. This is partially captured in JWQL-195

[stscijgbot-jwql]

Comment by Bryan Hilbert on JIRA:

In #1102 which the jira bot never mirrored, MIRI asks for a better stretch in the preview images. This could be done as part of these improvements.